CWA 17890:2022

SLOVENSKI STANDARD
SIST CWA 17890:2022
01-november-2022
Navodilo za uporabo hladnih površin na ovoju stavb za ublažitev učinkov
mestnega toplotnega otoka
Guide to the implementation of cool surfaces for buildings’ envelope to mitigate the
Urban Heat Island effects
Leitfaden für die Implementierung kühler Oberflächen für die Gebäudehülle zur
Milderung des Urban Heat Island Effektes
Ta slovenski standard je istoveten z: CWA 17890:2022
ICS:
13.020.20 Okoljska ekonomija. Environmental economics.
Trajnostnost Sustainability
91.060.20 Strehe Roofs
SIST CWA 17890:2022 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

SIST CWA 17890:2022
SIST CWA 17890:2022
CEN
CWA 17890
WORKSHOP
September 2022
AGREEMENT
ICS 13.020.20; 91.060.20
English version
Guide to the implementation of cool surfaces for buildings'
envelope to mitigate the Urban Heat Island effects
This CEN Workshop Agreement has been drafted and approved by a Workshop of representatives of interested parties, the
constitution of which is indicated in the foreword of this Workshop Agreement.

The formal process followed by the Workshop in the development of this Workshop Agreement has been endorsed by the
National Members of CEN but neither the National Members of CEN nor the CEN-CENELEC Management Centre can be held
accountable for the technical content of this CEN Workshop Agreement or possible conflicts with standards or legislation.

This CEN Workshop Agreement can in no way be held as being an official standard developed by CEN and its Members.

This CEN Workshop Agreement is publicly available as a reference document from the CEN Members National Standard Bodies.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,
Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of North
Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and United Kingdom.

EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2022 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members.

Ref. No.:CWA 17890:2022 E
SIST CWA 17890:2022
Contents Page
European foreword . 3
Introduction . 6
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 8
4 EU strategic context and benefits to use cool materials . 11
4.1 Green deal . 11
4.2 Benefits and opportunities to use cool materials . 12
4.2.1 Conditions to integrate cool materials (when and for what kind of project) . 12
4.2.2 Benefits to use cool materials . 13
4.3 Limitations of the document . 18
5 Presentation of cool materials (specifics and potentials to mitigate the Urban Heat
Island effects) . 20
5.1 Identification of cool materials for a project . 20
5.1.1 Cool roof properties . 20
5.1.2 Residential buildings . 22
5.1.3 Non-Residential Buildings . 27
5.2 Cool roof materials . 36
5.3 Installation of cool material and implementation of cool roofs . 39
5.4 Ageing and durability of cool roofs properties . 40
5.5 Maintenance of cool roof materials . 42
5.6 Financial impacts along the value chain . 43
6 From building to district and district to territory implementation . 44
6.1 Performance at building level (inside and outside) of cool roofs . 44
6.2 Performance at the district level . 45
6.3 Performance at territory level . 45
Annex A (informative) Roadmap for standardization . 47

A.1 Status of CWA . 47
A.2 Benefits of standardization . 47
A.3 Check-list before moving toward standardization . 48
Bibliography . 50

SIST CWA 17890:2022
European foreword
This CEN Workshop Agreement (CWA 17890:2022) has been developed in accordance with the CEN-
CENELEC Guide 29 “CEN/CENELEC Workshop Agreements – A rapid prototyping to standardization” and
with the relevant provisions of CEN/CENELEC Internal Regulations - Part 2. It was approved by a
Workshop of representatives of interested parties on 2022-04-14, the constitution of which was
supported by CEN following the public call for participation made on 2021-07-06. However, this CEN
Workshop Agreement does not necessarily include all relevant stakeholders.
The final text of this CEN Workshop Agreement was provided to CEN for publication on 2022-06-29.
The following organizations and individuals developed and approved this CEN Workshop Agreement:
Bernard Gindroz - Chairperson
Giuliana BONVICINI Centro Ceramico
Jonathan BOUVIER LNE - Laboratoire national de métrologie et d'essais
Emmanuel BOZONNET Université de la Rochelle -
Nigel CHERRY BMI Group and CEN/TC 128
Massimo CUNEGATTI Soprema/ESWA
Mario CUNIAL Industrie Cotto Possagno S.p.A.
David DA SILVA ENGIE
Alexandre DHOTEL IKO SAS
Alfonsina DI FUSCO Confindustria ceremica
Elisa DI GIUSEPPE Università Politecnica delle Marche
Maxime DOYA TIPEE
Andréas DRECHSLER BMI Group
Marielle FASSIER CTMNC
Paris FOKAIDES Frederick University
Bernard GINDROZ Gindroz Bernard
Maria-José GONZALEZ Afnor
Louis GORINTIN ENGIE
Hans-Juergen HOFMANN Amberger Kaolinwerke Eduard Kick GmbH & Co.KG
Angela HULLIN Amberger Kaolinwerke Eduard Kick GmbH & Co.KG
Alain KOENEN LNE - Laboratoire national de métrologie et d'essais
Maria KOLOKOTRONI Brunel University London
Denia KOLOKOTSA ECRC/TUC
Evangelia KONTOU KALOMOIRI Thermacote Inc.
Martin LONDSCHIEN CEN/TC 254/SIKA
Yves MADEC BMI Group
Alberto MADELLA SITEB/Gruppo PRIMI and EWA
SIST CWA 17890:2022
Niklaus MARGADANT Eternit (Schweiz) AG
Milena MARTARELLI Università Politecnica delle Marche
Heinz MEIER SIKA Services AG/ECRC Certification Board
Stephan MERKLEIN BMI Group
Giovanni MURANO CTI
Christiana PANTELI Cleopa GMBH
Rémi PERRIN Soprema
Jonas PIGEON ENGIE
Gloria PIGNATTA University of New South Wales
Alkistis Plessis-MOUTAFIDOU CERIB
Sahar SAIAGH ENGIE
Agnese SALVATI Brunel University London
Lieven SANDERS Wienerberger
Mattheos SANTAMOURIS University of New South Wales
Hans – Peter SPRINGINSFELD WKO (Wirtschaftskammer Österreich)/ASI
Simona SCHRAMMEL Prospex Institute
Jouko VYORYKKA Dow Europe GmbH
Rupert WOLFFHARDT Holzforschung
Dimitrios XILAS ECRC/TUC
SIST CWA 17890:2022
Attention is drawn to the possibility that some elements of this document may be subject to patent rights.
CEN-CENELEC policy on patent rights is described in CEN-CENELEC Guide 8 “Guidelines for
Implementation of the Common IPR Policy on Patent”. CEN shall not be held responsible for identifying
any or all such patent rights.
Although the Workshop parties have made every effort to ensure the reliability and accuracy of technical
and non-technical descriptions, the Workshop is not able to guarantee, explicitly or implicitly, the
correctness of this document. Anyone who applies this CEN Workshop Agreement shall be aware that
neither the Workshop, nor CEN can be held liable for damages or losses of any kind whatsoever. The use
of this CEN Workshop Agreement does not relieve users of their responsibility for their own actions, and
they apply this document at their own risk. The CEN Workshop Agreement should not be construed as
legal advice authoritatively endorsed by CEN/CENELEC.
SIST CWA 17890:2022
Introduction
By 2050, according to UN projections, the world population is expected to reach ten billion people. Today
half of the population is living in cities and projections show more than 80 % by 2050. Cities are where
80 % of global GDP is produced, but they are also where 70 % of the energy is consumed and 75 % of
waste and Greenhouse Gas (GHG) emitted.
Abating GHG emissions and increasing energy efficiency are at the heart of our European strategy and
regulatory framework, with a focus on cities and built areas that offer a high potential for improvement
and for meeting the EU Green Deal objectives. Urban Heat Island effect is one important topic both to
mitigate climate change and to adapt. Minimizing these Urban Overheating effects contributes to
reducing energy consumption by lowering energy demand for cooling and ventilation during hot periods,
and thus the related GHG emissions , as well as to bringing better comfort to citizens.
This document presents guidelines about why, when, and how to consider mitigation of Urban Heat
Island effects with cool roofs and cool materials, as well as reference information about characteristic
parameters and how to select appropriate materials.
Cool materials are especially of high importance for new buildings and constructions but also for
retrofitting of existing built infrastructures. A cool material is characterised by higher solar reflectance
in comparison to conventional roof materials displaying the same colour and high infrared emittance
values. Cool roofing products can be applied to all types of roofs including those of residential buildings,
apartment blocks, industrial and commercial buildings, hospitals, and offices.
The benefits are direct and numerous, such as reducing the cooling energy consumption and even leading
to avoiding the installation of air conditioning, by keeping temperature indexes lower around Renewable
Energy Systems (i.e. Photovoltaic) and thus maintaining higher efficiency and longer life of these pieces
of equipment, by extending the life of the roofing materials, and of course by keeping the surrounding
temperature lower, which impacts the quality of life and health.
This document will also contribute to setting common elements of language (terms and definitions) and
raising awareness among decision-makers, urban planners and constructors, both private and public, and
among investment institutions and investors, about the benefit of cool materials, as well as guiding them
towards the selection of appropriate solutions against Urban Heat Island effect with immediate and long-
term multi-benefits.
Whilst the guide focuses on cool materials for roofs it is also relevant to other parts of the building
envelope, other construction and built infrastructures, including roads and pavements, by aligning terms
and definitions as well as considerations about characteristics of cool materials.

This document is not intended to address consideration about carbon footprint of materials.
SIST CWA 17890:2022
1 Scope
The document provides the terminology relating to cool materials and a guide to the implementation of
cool surfaces for building envelopes to mitigate the urban overheating effects. It concentrates on the
application to roofs.
The document will focus on urban areas for local authorities and building/construction owners.
The users of CWA 17890:2022 will be local authorities, urban planners for cities including construction,
infrastructures and landscape architects.
In addition, the terminology and characteristics of cool materials will serve as a reference for other
applications where the use of cool materials will have a significant contribution to adaptation to climate
change as well as quality of life, such as for roads and pavements.
Whilst reflective surfaces can be very beneficial, they are not a
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